JPH04307693A - Paper sheet or the like discriminating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper sheet discriminating device for discriminating paper sheets such as banknotes and securities.

0002

[Prior Art] Conventionally, automatic teller machines and automatic teller machines (A
In an automatic transaction processing device such as TM), a paper sheet discrimination device is incorporated in order to discriminate the authenticity, denomination, etc. of banknotes. FIG. 2 is a block diagram of a conventional paper sheet discrimination device. In the illustrated device, a one-dimensional image sensor is used to read reflected light from the top and bottom surfaces of banknotes.

The illustrated device includes an upper discriminating unit 30,
It consists of a lower discrimination unit 50. Upper discrimination unit 3
0 determines the authenticity, denomination, front and back of a banknote, etc. from the reflected light from the top surface of the banknote. The lower discrimination unit 50 discriminates the authenticity, denomination, front and back, etc. of a bill from the reflected light from the lower surface of the bill.

[0004] Each of these units operates completely independently, and both units perform discrimination processing for the entire banknote. That is, each of these units constitutes an independent unit. Upper and lower discrimination unit 30,
The optical system 50 includes LED array light sources 31, 51, LED lighting circuits 41, 61, convergent rod lens arrays 32, 52, and one-dimensional image sensors 33, 53.

[0005] The LED array light sources 31 and 51 are light sources for irradiating the upper and lower surfaces of the banknote M with light. LED
The lighting circuits 41 and 61 supply power to the LED array light sources 31 and 51 to light them. The focusing rod lens arrays 32 and 52 consist of a plurality of lens arrays, and are
The one-dimensional image sensor 3 detects the reflected light from the top and bottom surfaces of the
3 and 53. One-dimensional image sensor 33, 5
3 converts the reflected light from the banknote M into an analog electrical signal.

[0006] Also, upper and lower discriminating units 30 and 5
0 includes sensor control circuits 34 and 54 as control circuits,
sensor drive circuits 35, 55, amplifier circuits 36, 56,
A/D conversion circuits 37 and 57 are provided. The sensor control circuits 34 and 54 perform electrical control in the main scanning direction and mechanical control in the sub-scanning direction of the one-dimensional image sensor via the sensor drive circuits 35 and 55.

The sensor drive circuits 35 and 55 drive the one-dimensional image sensor 3 according to commands from the sensor control circuits 34 and 54.
It outputs the drive signals necessary for the operations of 3 and 53. The amplifier circuits 36 and 56 amplify analog electrical signals output from the one-dimensional image sensors 33 and 53 via the sensor drive circuits 35 and 55. A/D conversion circuits 37 and 57 convert analog electrical signals into digital signals.

Furthermore, an upper and lower discrimination unit 30,
50 is a recognition processing section 38, 58 as a processing circuit for discrimination.
, discrimination processing sections 39 and 59, and dictionary sections 40 and 60. The recognition processing units 38 and 58 are the A/D conversion circuit 3
7, 57 is recognized as image data, and characteristic image data is extracted. The discrimination processing sections 39 and 59 perform discrimination processing on the image data of the banknote M by comparing the image data recognized by the recognition processing sections 38 and 58 with the data stored in the dictionary sections 40 and 60.

The dictionary sections 40 and 60 are composed of memories and the like. The dictionary data stored in this memory is the maximum value, minimum value, etc. of characteristic image data obtained from several thousand banknotes read in advance by the upper and lower discrimination units 30 and 50. Here, the processing operation of the upper discrimination unit 30 among the discrimination units having the above configuration will be explained. It goes without saying that the lower discrimination unit 50 also performs the same processing operations as the upper discrimination unit 30.

[0010] The banknote M is moved by an arrow Y by a conveyance roller (not shown) or the like.
When it is conveyed in the direction and reaches the reading position of the one-dimensional image sensor 33, the L
The top surface of the banknote M is illuminated by the ED array light source 31. Then, the reflected light is imaged on the one-dimensional image sensor 33 via the rod lens array 32. The reflected light that has been imaged passes through a sensor drive circuit 35 controlled by a sensor control circuit 34 on the one-dimensional image sensor 33.
is photoelectrically converted. The photoelectrically converted weak read signal is amplified to a predetermined level in the amplifier circuit 36, and then
In the D conversion circuit 37, for example, 8 bits per pixel (25
It is converted into a digital signal representing a multi-value density of 6 gradations). Thereafter, it is supplied to the next stage recognition processing section 38.

The recognition processing section 38 extracts the characteristic image data of the banknote M from the optical characteristic pattern of the pattern or figure on the top surface of the banknote M. For example, a multi-value level (hereinafter referred to as an envelope waveform) in the main scanning direction or sub-scanning direction is extracted, or the number of binary data binarized using a certain threshold value or an image pattern is extracted. This characteristic image data is then supplied to the next-stage discrimination processing section 39. The determination processing section 39 compares and determines the feature image data extracted by the recognition processing section 38 and reference dictionary data read out from the dictionary section 40. Thereby, the authenticity, denomination, front and back, etc. of the banknote M are determined on the top surface of the banknote M. next,
The operation of the sensor control circuit 34 that controls the image sensor 33 of the upper discrimination unit 30 will be explained.

FIG. 3 is a timing chart of conventional sensor control. FIG. 3(a) shows the sensor start signal. This is a signal that determines the reading start position of the one-dimensional image sensors 33 and 53 in the main scanning direction. Figure 3(b)
indicates the sensor clock signal. This is a signal for generating a sensor start signal. FIG. 3(c) shows a sensor read signal output from the image sensor. Figure 3(d) shows the LEDs that control the blinking of the LED array light source.
Indicates a control signal. This LED control signal means that the LED is turned on when it is "H" and turned off when it is "L". In this figure, it is shown that it is constantly lit.

The sensor start signal shown in the figure is generated for a certain period of time (
T0) is a periodic repeating signal. This signal is created by counting the basic clock of the sensor control circuit by a predetermined number using a combination of a counter circuit and a decoder circuit. Here, the counter circuit and the decoder circuit are composed of logic circuits. Further, the count value is stored in a look-up table ROM or the like. Generally, a paper sheet discrimination device incorporated in an automatic transaction device performs various discriminations based on information on both sides of a banknote in order to improve discrimination accuracy. Therefore, in addition to the upper discrimination unit 30, a lower discrimination unit 5 having exactly the same function as the upper discrimination unit 30 is provided.
0 is set. Using both of these units, the authenticity, denomination, front and back, etc. of the banknote M are determined based on the entire banknote M.

[0014]

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has the following problems. That is, in the conventional paper sheet discriminating device, discriminating units having the same function are arranged at two locations, upper and lower. In other words, components such as optical system parts, various control circuits, and discrimination processing circuits,
There was a problem in that two systems were required for each. Also,
The optical system components must be arranged so that the transmitted light from the vertically opposed discrimination units does not leak into each reflected light component. That is, the upper discrimination unit 30 and the lower discrimination unit 50 must read different parts of the banknote M.

[0015] Therefore, due to the increase in the number of various control circuits and discrimination processing circuits, the physical scale of the paper sheet discrimination apparatus has increased. This has resulted in the problem of increased costs for automatic transaction processing devices. The present invention has been made with attention to the above points, and there are problems related to the physical size of the paper sheet discriminating device due to the use of two discriminating units, upper and lower, and the position of the optical system related to the arrangement of the units. The object of the present invention is to provide a small, low-cost paper sheet discrimination device that eliminates dots.

[0016]

[Means for Solving the Problems] The paper sheet discriminating device of the present invention includes a lighting means for alternately lighting a plurality of light sources that illuminate both sides of a paper sheet in synchronization with the reading cycle of an image sensor; a sensor control means that performs control to alternately extract only read signals due to reflected light from the paper sheets from image sensor read signals obtained from both sides of the paper sheets illuminated by a plurality of light sources; A recognition processing means that performs a process of extracting a single feature image data from a double-sided reading signal, and a discrimination processing means that discriminates paper sheets based on the feature image data created by the recognition processing means. It is characterized by this.

[0017]

[Operation] In the paper sheet discriminating device of the present invention, the plurality of light sources that illuminate both sides of the paper sheet are alternately turned on by the lighting means in synchronization with the reading cycle of the image sensor. On the other hand, the image sensor obtains read signals from both sides of the paper sheet illuminated by a plurality of light sources. Then, the sensor control means alternately extracts only the read signals caused by the reflected light from the paper sheets from among the read signals. Thereafter, single characteristic image data is extracted from the reading signals of both sides of the paper sheet, and the paper sheet is discriminated based on the characteristic image data. Therefore, both sides of paper sheets can be read with a single unit.

[0018]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the paper sheet discrimination device of the present invention. The illustrated paper sheet discriminating device consists of a single discriminating unit. A banknote M in the figure is a banknote to be discriminated by the paper sheet discrimination device. The illustrated device includes LED array light sources 1 and 21 and an LED lighting means 12 as an optical system.
, convergent rod lens arrays 2 and 22, and one-dimensional image sensors 3 and 23.

The LED array light source 1 is a light source for illuminating the upper surface of the banknote M in the drawing. LED array light source 2
Reference numeral 1 denotes a light source for illuminating the lower surface of the banknote M in the figure. The LED lighting means 12 includes LED array light sources 1 and 21.
Lighting is performed by alternately supplying power to the The focusing rod lens array 2, 22 consists of an array of a plurality of lenses,
Reflected light from the upper and lower surfaces of the banknote M is collected onto the one-dimensional image sensors 3 and 23. one-dimensional image sensor 3,
23 converts the reflected light from the banknote M into an analog electrical signal.

The illustrated device also includes a sensor control means 11, sensor drive circuits 4 and 24, amplifier circuits 5 and 25, A/D conversion circuits 6 and 26, and a multiplexer 7 as control circuits. ing. The sensor control means 11 performs electrical control in the main scanning direction and mechanical control in the sub-scanning direction of the one-dimensional image sensors 3 and 23 via the sensor drive circuits 4 and 24. The sensor drive circuits 4 and 24 drive the one-dimensional image sensors 3 and 23 according to commands from the sensor control means 11.
Outputs the drive signals necessary for operation.

The amplifier circuits 5 and 25 amplify analog electrical signals output from the one-dimensional image sensors 3 and 23 via the sensor drive circuits 4 and 24. A/D conversion circuit 6, 26
converts analog electrical signals into digital signals. The multiplexer 7 switches the digital signals A and B and inputs them to the recognition processing means 8 at the next stage.

Furthermore, the illustrated apparatus includes a recognition processing means 8, a discrimination processing means 9, and a dictionary section 1 as a discrimination processing circuit.
0. The recognition processing means 8 recognizes the digital signals input through the A/D conversion circuits 37 and 57 as image data, and extracts characteristic image data. The discrimination processing means 9 performs data discrimination processing by comparing the image data recognized by the recognition processing means 8 with the data stored in the dictionary section 10. The dictionary section 10 is composed of a memory and the like. The dictionary data stored in this memory is the maximum value, minimum value, etc. of characteristic image data obtained from several thousand banknotes read in advance by the illustrated device.

Next, the operation of the above-mentioned apparatus will be explained. When the banknote M is transported in the direction of arrow Y by a transport roller (not shown) or the like and reaches the reading position of the one-dimensional image sensors 3 and 23,
The upper surface of the banknote M is illuminated by the LED array light source 1. Then, the reflected light is imaged on the one-dimensional image sensor 3 via the rod lens array 2. The imaged reflected light from the upper surface is photoelectrically converted on the one-dimensional image sensor 3 under the control of the sensor drive circuit 4. The photoelectrically converted weak reading signal is amplified to a predetermined level by an amplifier circuit 5, and then converted into a digital signal representing a multi-value density of 8 bits per pixel (256 gradations) by an A/D converter circuit 6, for example. is converted to Thereafter, the signal is supplied to the input terminal A of the multiplexer 7 at the next stage.

On the other hand, the light reflected from the bottom surface of the bill M is also photoelectrically converted on the one-dimensional image sensor 23 under the control of the sensor drive circuit 24, and after being amplified to a predetermined level by the amplifier circuit 25, the light is converted into an A/D converter. The conversion circuit 26 converts the signal into a digital signal representing, for example, a multi-value density of 8 bits (256 gradations) per pixel. The signal is then supplied to the input terminal B of the multiplexer 7 at the next stage.

Next, the processing of the recognition processing means 8, discrimination processing means 9, and dictionary section 10 after the multiplexer 7 is as follows. The upper surface and lower surface reading signals inputted to the multiplexer 7 are switched line by line by the multiplexer 7, and each valid data is sent to the recognition processing means 8.
is input. In the recognition processing means 8, characteristic image data is extracted from the reading signals of the upper and lower surfaces of the banknote M by signal processing to be described later, and is inputted to the next-stage discrimination processing means 9. The discrimination processing means 9 determines the authenticity of the banknote M based on the information obtained from the entire banknote M by comparing the characteristic image data from the recognition processing means 8 and the standard dictionary data of the dictionary section 10.
Distinguish the denomination, front and back, etc.

The operation of the sensor control means 11 that controls the one-dimensional image sensors 3 and 23, the LED lighting means 12, and the multiplexer 7 of this embodiment will now be described. FIG. 4 is a timing chart of sensor control according to the present invention. FIG. 4(a) shows a sensor start signal. this is,
This signal determines the reading start position of the one-dimensional image sensors 3 and 23 in the main scanning direction. FIG. 4(b) is a sensor clock signal. This is a signal for generating a sensor start signal. FIG. 4(c) shows the top LED control signal. This is a control signal for the LED array light source 1 that illuminates the top surface of the banknote M, and "H" indicates lighting and "L" indicates turning off. FIG. 4(d) shows the bottom LED control signal. This is an LED array light source 21 that illuminates the bottom surface of the banknote M.
This is a control signal for "H" to turn on the light and "L" to turn off the light.

FIG. 4(e) shows the top sensor read signal. This is a read signal output from the one-dimensional image sensor 3 on the top surface of the banknote M. FIG. 4(f) shows the bottom sensor read signal. This is a read signal output from the one-dimensional image sensor 23 on the bottom surface of the banknote M. Further, FIG. 4(g) shows a multiplexer input switching signal. By inputting this signal, multiplexer 7 switches between signals A and B. That is, for example,
It is controlled so that signal A is output at "H" and signal B is output at "L". As a result, the A/D converted reading signals of the upper surface sensor and the lower surface sensor are alternately outputted line by line to the output terminal of the multiplexer 7, as shown in FIG. 4(h).

Now, to explain the sensor control, the sensor start signal is generated by counting the basic clock of the sensor control means 11 by a predetermined number using a combination of a counter circuit and a decoder circuit. In addition, this sensor start signal causes the upper and lower LED control signals (
The polarities of c), (d) and the multiplexer input switching signal (g) are alternately inverted line by line as shown.

For example, when starting edge information is input to the sensor control means 11 from a detector (not shown) that detects the leading edge of the banknote M incorporated in the banknote M conveying system, The sensor control means 11 is initialized with the sensor start signal. Then, the polarity of each subsequent control signal is changed to the LED on the top surface of the banknote M on an odd number line as shown in the figure.
The array light source is controlled so that the lower LED array light source is turned on in even-numbered lines. As a result, the reading signal obtained from the one-dimensional image sensor 3 on the top surface is obtained from the reading signal of transmitted light from the bottom LED array light source 21 on the odd numbered lines, and from the light reflected from the top surface of the banknote M by the top LED array light source 1 on the even numbered lines. It becomes a read signal.

On the other hand, in the read signal obtained from the one-dimensional image sensor 23 on the bottom surface, the odd-numbered lines are the read signals obtained from the light reflected from the bottom surface of the banknote M by the bottom LED array light source 21, and the even-numbered lines are the read signals obtained from the top surface LED array light source 1. This becomes the read signal of the transmitted light. Here, the switching signal in the multiplexer 7 is controlled so that the input signal of the input terminal B is outputted on the odd numbered line and the input signal of the input terminal A is outputted on the even numbered line. Then, in the reading signal outputted from the multiplexer 7 and supplied to the next stage recognition processing means 8, the odd-numbered lines are the reading signals from the lower surface of the bill M, and the even-numbered lines are the reading signals from the reflected light from the upper surface of the bill M.

In the apparatus having the above configuration, an embodiment has been shown in which the digital signal multiplexer 7 is used at the output terminals of the upper and lower A/D conversion circuits 6 and 26, but as another embodiment, it is possible to use the upper and lower amplifier circuits. Using analog switch circuits etc. at the output terminals of 5 and 25, switching is performed line by line, and the output signal is
It is also possible to make the signal processing system into one system by inputting the signal to the /D conversion circuit.

Next, from the reading signals of the upper and lower two screens obtained as described above, various signal processing is performed in the recognition processing means 8 of the next stage, and the optical characteristic pattern of the banknote M used for reading is obtained in one screen. A method for extracting as feature image data will be explained. The read signal input to the recognition processing means 8 is
As mentioned above, the odd-numbered lines are the read signals from the bottom surface of the bill M, and the even-numbered lines are the read signals from the reflected light from the top surface of the bill M, and each pixel is 8.
This is a digital signal representing multi-value density of bits (256 gradations). As a process before extracting characteristic image data from this read signal, the following process is performed, for example, at the stage of writing into a frame memory (not shown) or the like.

FIG. 5 is a conceptual diagram of preprocessing in the present invention. Optical feature pattern 71 on the top surface of banknote M and banknote M
The optical feature pattern 72 on the lower surface is, for example, as shown in the figure. If the read signals of these characteristic patterns are sequentially written line by line into the frame memory,
The data will be as shown in the characteristic pattern 73.

If the address space of the frame memory is divided in advance into a space for odd-numbered lines and a space for even-numbered lines, and the read signals of the respective corresponding lines in the read signals are sequentially written, data as shown in the characteristic pattern 74 is obtained. becomes. In addition, by using a one-line buffer memory, for example, by comparing odd lines (lower side of banknote M) and even lines (upper side of banknote M), the level difference, ratio, or average value of each pixel can be calculated in a frame. When sequentially written into the memory, the data becomes as shown in the characteristic pattern 75. Note that the amount of data in this case is half of the total amount of data.

After performing the above pre-processing, the characteristic image data of the banknote M is extracted, for example, by extracting an envelope waveform in the main scanning direction or sub-scanning direction, or by extracting binary data binarized using a certain threshold value. The number and image pattern are extracted and supplied to the next stage discrimination processing means 9, and the dictionary section 1
By comparison with dictionary data starting from 0, the authenticity, denomination, front and back, etc. of the upper and lower surfaces of the banknote M are determined.

[0036]

As explained above, according to the paper sheet discriminating device of the present invention, among the components of the discriminating unit, various control circuits and discriminating processing circuits are shared on both sides of the paper sheet. This makes it possible to downsize the device and reduce costs. Further, by performing signal processing such that two types of screen reading signals obtained from both the upper and lower surfaces can be treated as characteristic image data of one screen, the determination processing time can be shortened. Furthermore, by alternately lighting the LED array light source that illuminates the paper sheet line by line, it is possible to eliminate restrictions on the arrangement of the optical systems of the upper and lower determination units. Therefore, it is possible to realize a paper sheet discrimination device that is small in size, inexpensive, and has a quick judgment processing time.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a paper sheet discrimination device of the present invention.

FIG. 2 is a configuration diagram of a conventional paper sheet discrimination device.

FIG. 3 is a timing chart of conventional sensor control.

FIG. 4 is a timing chart of sensor control according to the present invention.

FIG. 5 is a conceptual diagram of preprocessing in the present invention.

[Explanation of symbols]

1, 21 LED array light source 2, 22 Focusing rod lens array 3, 23 One-dimensional image sensor 4, 24 Sensor drive circuit 5, 25 Amplifier circuit 6, 26 A/D conversion circuit 7 Multiplexer 8 Recognition processing means 9 Discrimination processing means 10 Dictionary section 11 Sensor control means

Claims (1)

[Claims] 1. Lighting means for alternately lighting a plurality of light sources that illuminate both sides of a paper sheet in synchronization with the reading cycle of an image sensor; a sensor control means for controlling the image sensor to alternately extract only reading signals caused by reflected light from the paper sheet from the reading signals of the image sensor; and extracting single characteristic image data from the reading signals for both sides of the paper sheet. A paper sheet discriminating device comprising a recognition processing means for performing processing, and a discrimination processing means for discriminating paper sheets based on characteristic image data created by the recognition processing means.